Post subject: Re: Off the dop - post YOUR latest creation
Posted: Sun Nov 21, 2021 4:17 am
Gemology Online Veteran
Joined: Sat May 22, 2010 2:51 am Posts: 755 Location: South Africa
Given its RIs, the enstatite I posted above is certainly enstatite itself, rather than bronzite or hypersthene. There were no problems with heat-sensitivity and I dopped it normally with brown wax. The cleavage and tendency to fray at some edges was problematic, so I cut the whole stone on a 1200 mesh sintered diamond lap. The stone also had fairly marked differential directional hardness. The softer facets tended to have a rougher surface, which required more polishing, so on the 1200# lap they had to be left a bit high to avoid over-polishing and compromising the meets. Polishing itself was easy with AlOx on a Gearloose Matrix lap.
Post subject: Re: Off the dop - post YOUR latest creation
Posted: Wed Nov 24, 2021 12:52 am
Valued Contributor
Joined: Thu May 28, 2009 4:13 am Posts: 222
Barbra Voltaire, FGG wrote:
Gene, astounding work. What was the color of the tanz before heating?
I found an old picture of tanzanites (well, zoisite) before heat treatment. It typically looks like this; a coca cola brown color, mixed with undertone of purple. The heat treatment will turn this into the classic purplish blue.
Gene, astounding work. What was the color of the tanz before heating?
Hi Barbra, The color was pretty similar to the images Dioptase posted. Unheated tanzanite normally has 3 strongly distinct color axis. So one is that root beer color, another in this case was a purple grayish, and the other a brown with a touch of blue. Some people heat the tanzanite before cutting so they can be sure which way to orientate the stone for more blue or purple. This one I heated after cutting.
Post subject: Re: Off the dop - post YOUR latest creation
Posted: Sat Dec 11, 2021 12:07 am
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Joined: Fri Dec 25, 2015 8:31 pm Posts: 276
8ct amethyst and a 2.5ct tourmaline. Took forever to cut the amethyst due to rain making poor lighting, resulting in mismeets. I'm pretty sure that if you take photographs on the towel you clean stones with, you don't get lint as long as the gem stays in contact with the towel.
Post subject: Re: Off the dop - post YOUR latest creation
Posted: Sat Dec 11, 2021 2:40 am
Valued Contributor
Joined: Fri Dec 25, 2015 8:31 pm Posts: 276
There's a little bit on the girdle facet of the tourmaline in the 8 o'clock direction, you might have to zoom the image to see but it's noticeable on the raw photo. The amethyst is a barion square with 32 pavillion facets cut at 42.6, and 16 crown facets cut at 32.0, gives some nice needle scintillation at this size.
Post subject: Re: Off the dop - post YOUR latest creation
Posted: Fri Feb 18, 2022 7:15 pm
Valued Contributor
Joined: Fri Dec 25, 2015 8:31 pm Posts: 276
I've been waiting on a dry cloudy day to take this shot - it's the best conditions for good garnet photos... Never cutting zircon on a 20-28 micron lap again! Heavy use of polish almost saved it but it really needs a 7-10 micron lap, a pity my supplier doesn't have those often. From top to bottom: -Zircon in Graham's "Flutter" with modifications -Rose Garnet in Herbst's "Green Flash" -Girasol Quartz in Keller's "Bar Round"
Post subject: Re: Off the dop - post YOUR latest creation
Posted: Sat Mar 12, 2022 11:30 pm
Valued Contributor
Joined: Fri Dec 25, 2015 8:31 pm Posts: 276
Two weeks of flooding rain kept this andalusite from being finished, very lucky the spot inclusions never broke the surface of the stone. How do you judge those when grading? I can see them with the naked eye but they can't be more than 0.1mm wide.
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